As an example of the existing power supply device for a vehicle, there is the type described in JP-A-2007-195336. Here, the power supply device for a vehicle of JP-A-2007-195336 is characterized in that in a hybrid automobile or electric automobile, an inverter that controls the operation of an accessory motor different from the motor for running also works as a converter for charging of the vehicle battery.
In JP-A-2007-195336, the accessory motor is explained with reference to a motor for driving a compressor for air conditioning as an example. Here, charge of the vehicle battery is carried out when the vehicle is stopped and the ignition key switch is turned off. Consequently, in this case, there is no need to turned on the accessory motor (compressor for air conditioning), so that the inverter for the accessory motor is used as the converter for charge of the vehicle battery.
However, the inverter has multiple switch elements, which are controlled on/off by a driving circuit, and other electronic parts, and heating takes place in company with switching of the switching elements when the inverter is in operation, so that it requires an efficient cooling. The aforementioned JP-A-2007-195336 merely discloses that the inverter of the accessory motor also works for charge of the vehicle battery, and it has no description at all on how to combine and control the operation of air conditioner and charge of the vehicle battery from the viewpoint of cooling of the inverter.
In addition, the technology for cooling the inverter carried on the compressor for air conditioning by the refrigerant circulated in the refrigeration cycle is well known (for example, see JP-A-2004-100683), while there is no description with regard to a combination with the charge as explained above.